2017 US Open – Women's singles

Sloane Stephens defeated Madison Keys in the final, 6–3, 6–0 to win the women's singles tennis title at the 2017 US Open. It was her first major title. Stephens was the first player using a protected ranking to win a major title, and the second unseeded woman in the Open Era to win the US Open (after Kim Clijsters in 2009). It was the first all-American final at the US Open since 2002; for the first time at a major since the 1985 Wimbledon Championships, all four semifinalists were American, and all from the same country overall. Angelique Kerber was the defending champion, but was defeated in the first round by Naomi Osaka. Kerber was the second US Open defending champion to lose in the first round, after Svetlana Kuznetsova in 2005. Osaka would go on to win the title the next year. Garbiñe Muguruza became the new world No. 1 after Karolína Plíšková failed to defend her finalist points. Eight of the top nine seeds (with the exception of Kerber) were in contention for the top ranking. This was Maria Sharapova's first major since the 2016 Australian Open, following a suspension for violating anti-doping rules. She was awarded a wildcard into the main draw, and was defeated by Anastasija Sevastova in the fourth round. Venus Williams became the first player in history to reach the semifinals of the US Open 10 years apart and then do so another 10 years apart, in 1997 (at 17 years, 79 days old), 2007, and 2017 (at 17 years, 79 days old). Her younger sister, Serena Williams, would join her in doing so at the 1999 (at 17 years, 348 days old), 2009, and 2019 (at 37 years, 344 days old) US Opens. Kaia Kanepi was the first qualifier to reach the quarterfinals since Barbara Gerken in 1981, and was the lowest-ranked player ever to reach a major quarterfinal, being ranked No. 418. This was the final major appearance for former world No. 1 Jelena Janković, who lost to Petra Kvitová in the first round. Janković would formally retire from tennis five years later.